400262981 has 2 divisors, whose sum is σ = 400262982. Its totient is φ = 400262980.

The previous prime is 400262969. The next prime is 400262983. The reversal of 400262981 is 189262004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 339812356 + 60450625 = 18434^2 + 7775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400262981 is a prime.

It is a super-2 number, since 2×400262981² = 320420907918012722, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 400262983, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400262983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200131490 + 200131491.

It is an arithmetic number, because the mean of its divisors is an integer number (200131491).

Almost surely, 2^400262981 is an apocalyptic number.

It is an amenable number.

400262981 is a deficient number, since it is larger than the sum of its proper divisors (1).

400262981 is an equidigital number, since it uses as much as digits as its factorization.

400262981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 400262981 is about 20006.5734447456. The cubic root of 400262981 is about 736.9677360689.

The spelling of 400262981 in words is "four hundred million, two hundred sixty-two thousand, nine hundred eighty-one".